• 1. The cutting edge needs to be how many more times harder than the workpiece material?

  A3 times harder than the workpiece. B1 time harder than the workpiece. CDoes not really matter.

• 2. When machining is carried out what happens at the cutting edge?

  AThe cutting edge is subjected to impact and some heat. BThe cutting edge is subjected to severe impact and extremely high temperatures. CThe cutting edge should be 3 times harder than that of the workpiece material.

• 3. In which year did General Electric release cemented carbides?

  A1928. B1923. C1941.

• 4. In comparison with dissolved high speed steels sintered high speed steels offer;

  ALower traverse rupture strength and regrindability. BHigher traverse rupture strength and regrindability.

• 5. Within cemented carbides there are 2 types straight carbide(WC-Co) and mixed carbides (WC-TiC-TaC-Co). Which of the following is incorrect?

  AIn mixed carbides TiC and TaC are added to improve the overall thermo-chemical stability. Therefore making them suitable for machining P and M class workpiece materials. BStraight carbides have lower thermo-chemical stability but the bonding strength between WC-Co is higher therefore making them more effective against impact strength. CMixed carbides are recommended for all types of workpiece materials.

• 6. Micro-grain cemented carbides that have grain sizes less than 1µm offer high hardness and traverse rupture strength. If used under high cutting edge temperature conditions;

  AWelding is reduced. BLess flank wear occurs. CLarge crater wear can occur.

• 7. As the hardness of a workpiece increases what can happen?

  AThe amount of welding can increase. BThe amount of flank wear can increase. CThe chips become more difficult to break.

• 8. Cermet tool grades, base of TiC-TiN with a binder of Ni, are superior to carbide grades in reference to surface finishes. However adhesion to the binder is lower than that of carbide grades. Therefore;

  ACermets cannot be used for rough machining. BCermets cannot be used for finish machining.

• 9. PVD coating is generally a single layer coating, whereas CVD coating is a multilayer coating. Which of the following is correct?

  ACVD coatings can be used only on selected substrates. BPVD coatings cannot provide a sharp cutting edge. BCVD coatings have lower thermo-stability when compared to PVD coatings.

• 10. Which of the following is not an advantage of PVD coatings?

  AHigh adhesion strength between the coating layer and substrate. BPVD coatings can provide a sharp cutting edge. CPVD coating surface is smooth.
• Next
• Try again

Result